NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescope have discovered a dim, star-like body that surprisingly is as frosty as Earth's North Pole. This "brown dwarf" is only 7.2 light years away, making it one of the sun's nearest neighbors.

Using NASA's Kepler Space Telescope, astronomers have discovered the first Earth-size planet orbiting a star in the "habitable zone" -- the range of distance from a star where liquid water might pool on the surface of an orbiting planet.

Next year, with the assistance of the world's only twin astronauts, NASA will conduct an unprecedented experiment in human biology. While one twin remains on the ground, the other will circle Earth onboard the International Space Station for a full year. Will the twins still be identical when they are re-united? The answer could help NASA make space travel safer for generations of astronauts to come.

NASA's Cassini spacecraft and Deep Space Network have uncovered evidence that Saturn's moon Enceladus harbors a large underground ocean of liquid water, furthering scientific interest in the moon as a potential home to extraterrestrial microbes.